Apparatus for controlling the movement of vehicles on railroads



1932- L F. J. SPRAGUE 1,869,627

APPARATUS FOR CONTROLLING THE MOVEMENT OF VEHICLES ON RAILROADS Original Filed April 12, 1927 WWL A TTORNEYS.

Patented Aug. 2, 1932 UNITED STATES PATENT OFFICE FRANK J. SPRAG'UE, OF NEW YORK, N. Y., ASSIGNOR TO SPRAGUE SAFETY CONTROL 86 SIGNAL CORPORATION, OF NEW YORK,

N. Y., A CORPORATION OF VIRGINIA APPARATUS FOR CONTROLLING THE MOVEMENT OF VEHICLES ON BAILROADS Original application filed April 12, 1927, Serial No. 183,

Serial No.

This application is filed as a division of my prior application, Ser. No. 183,193 of April 12, 1927, for apparatus for controlling movement of vehicles on railroads, and the subject hereof forms part of the apparatus disclosed in the betoresaid application.

My invention relates to an improvement in automatic train control systems, and particularly to the features known as forestalling and resetting, the former being an operation by which the engineer may, by the performance of a suitable manual act, prevent the coming on of an automatic brake appli cation, and the latter an operation by which the brake controlling apparatus may be restored to normal condition, after which the brakes (if applied) may be released and free running conditions established.

In much of present practice the forestalling and resetting operations are efiected by mechanisms differently placed, the forestalling being done in the cab, and the resetting through a switch or other device situated at such an inconvenient point as will require the train to be stopped before it can be used, so as to prevent release of the brakes, applied in response to a track initiated impulse, before the train has come to rest, although sometimes this reset switch is made inconvenient but possibly accessible when moving at slow speeds.

To place some restriction upon the act of forestalling, which unless limited by the condition that a train must actually braked or has had its speed reduced to some predeter mined rate-although present practice and rules actually permit forestalling at any speed and without any pre-application of the brakesit has been proposed to limit the time period in which the engineer may forestall an automatic brake I application when receiving a track impulse. This is done in certain electrically controlled systems by connecting a forestalling switch and circuits so that after manual operation of the switch by the engineer the forestalling circuit will be closed. and the essential circuit will be maintained for only a limited time, the movement of the switch handle initiating a motive force which after a short interplace as a result of passing a stop indication 193. Divided and this application filed July 6, 1929. 376,401.

val will open the essential circuit, just as the pilot circuits are made and opened in my Letters Patent No. 660,065 on the multiple-unit system oftra-in control.

With this arrangement, the engineer, on approaching a stop indication point within a distance less than he will cover in a predetermined time, which maybe anything from a hundred to a thousand feet or more, according tothe speed of a train, moves his switch to the forestalling position, closes the. forestalling circuit and initiates the motive force, which will open the essential circuit automatically in a predetermined time-say 15 seconds. After passing the stop indication point, if he returns the switch to the normal position within the time period there will be no automatic bra-king, although some part of the equipment may be responsive. But if the switch is held in the forestalling position for longer than the time period the brakes Will come on.

Thus there are three conditions in which the automatic brake application may take point. First, it the engineer does nothing; second, if he forestalls too soon; and, finally, if he holds on too long. Any of these condi tions may possibly act adversely as regards train movement's.

With the automatic brake application in efl'ect, the amount'of braking is made such as to bring the train to a stop, after which the engineer or fireman must get down from the cab, or climb out to a position diificult of access when the locomotive is moving, to reset the brake initiating apparatus, so that the engineer may release the brakes manually.

The main object of thus separating the forestalling and resetting actions, andproviding a time limit is to induce some measure of alertness on the part of the engineer, under possible penalty, and to insure that once the brakes have actually come on automatically the train shall be stopped before the engineer can release them.

There are serious objections to both prac tices, and specifically to the lack of restriction of the use of a forestalling device, as

well as to the necessity for getting out of-the cab to enable the brakes to be released. This latter act cannot be performed at times without serious danger, as in tunnels, snow-sheds and on trestles, or in proximity to passing trains and under conditions of poor visibility.

I desire, therefore, to provide definite limitations upon the act of forestalling, as well as upon the act of resetting, While the timing mechanism for opening the forestalling circuit may be omitted entirely. I plan, also, to combine in a single mechanism-operated in the cab-both the forestalling and resetting operations, and for compelling, under possible penalty, acknowledging of the receipt of a brake initiating impulse from the track. This mechanism may conveniently be referred to as an acknowledging device.

My invention will conduce to safety and convenience, and eliminate delays, while making it possible to impose upon the engineer such precautionary conditions as are essential to safe operation and the maintenance of the fundamentals of automatic train control sys tems.

The accompanying drawing and specification illustrate my invention as applied to a system of automatic train control which cooperates with the usual type of air brake equipment in whole or in part. It is of course applicable not only to vehicles propelled by steam but to vehicles otherwise propelled, It should be noted that the mechanic, electric and pneumatic devices shown in this drawing serve merely to illustrate the nature of the invention, and thus do not limit it to the construction shown.

In the accompanying drawing which forms a part of this application- Figure 1 is a diagrammatic illustration of the electric circuits of the vehicle-carried equipment of a train control system incorporating my invention, also indicating in a schematic way the cooperating track elements.

Fig. 2 is an enlarged sectional view of the sylphon-operated contactor B of Fig. 1.

Fig. 3 is a diagrammatic perspective view of the rotatable contactor mechanism used for the acknowledging device of Fig. 1.

Figures 3a and 3b are developments of the rotatable cont-actor 106 of Fig. 3; Fig. 3a, illustrating the relative position of the rotatable contacts and the stationary contacts in the normal position of the acknowledging device, and Fig. 3b illustrating these contacts in the operated position.

Relay R represents the governing element of the circuits. This relay is normally energized, its maintaining circuit being the following: From the positive side of the battery H, contactor A, contacts 7, 6, armature 2, and coil of relay R, back to the negative battery. As the maintaining circuit of relay R includes its own armature 2 it is a stick relay which, when once de-energized, canerning element of the circuits which element is herein illustrated as a stick relay. The contactor A is for convenience illustrated as biased by a spring 18 and is intended to be controlled by track elements. In the specific illustration it is normally held by its spring against its cooperating contact so as to close the maintaining circuit of relay R. However, if an active application track element is passed the contactor A is so affected as to open the maintaining circuit of relay R at contact 7.

The word active in this connection refers to the condition of the track element which is intended to initiate automatic braking and does not refer to the inherent condi tion of the track element itself. The term track element is likewise employed in its broadest sense irrespective of the type of system, whether continuous or intermittent, to which my invention is applied.

For illustrative purposes I have indicated in schematic way an intermittent inductive type of system, such being fully described in my British Patent #t1t9,922. or my United States Patent #1,669,165 of May 8, 1928. The track element is represented by an application magnet of the compound type which consists of a permanent magnet m pro vided with soft iron poles m m surrounded by neutralizing coils n n. The neutralizing coils n are energized from a battery 150 for clear trafiic conditions in which case their field neutralizes or deflects the field of the permanent magnet. For restricted traiiic conditions, however, the neutralizing coils are de-energized in which case the flux of the permanent magnet is effective and the track element active. The trafiic control is shown in a conventional way. The receiver of the locomotive is represented by plates p which collect the flux when passing over an active magnet, whereby the a mat re A is magnetically attracted by the plates p and breaks the circuit of which it forms part.

The stick relay R- normally maintains its armature 1 against a contact 4c in the normally closed circuit of an electro-pneum atic vent valve V.

The vent valve V represents the connecting member between the electric and pneumatic parts of the vehicle-carried equipment. deenergization of which initiates an automatic brake application: various pneumatic equipment may 3e used in connection with my inventionfor instance, the one described in my previously referred to application, Ser. No. 183,193 of April 12, 1927.

The vent valve V is normally energized through the following circuit; from the positive side of the battery H, through contact 14, strip contact u and contact 15 of the acknowledging device-this device being more fully described hereafter-through coil 20 of the vent valve, contact 4, and armature 1 of relay R, back to the negative side of the battery.

As mentioned previously, when the stick relay R is de-energized, as happens when passing over an active application track element, it cannot be re-energized by way of its normal maintaining circuit, even if such track element is passed and contactor A has assumed its normal position; such re-energization can only take place by way of re-energizing circuits, these circuits being governed partly by an acknowledging device F and partly by a sylphon-operated contactor B or a speed governor M.

The acknowledging device consists mainly of a rotatable contactor mechanism, as shown in Fig. 3. It consists mainly of a shaft 109, on which is fixedly mounted a handle 105 and a rotatable contactor 106, this contactor being maintained in its normal running position by a spring 107, this spring being anchored to some suitable fixed part illustrated by pin 108. The device may be put in operative position by moving the handle 105, which is preferably associated with suitable stops, in the direction shown by the arrow. On the rotatable contactor 106 are two metal strip contacts; a long strip a forming an almost closed ring, being broken only by a short insulation w, and a short Inetal strip aZ opposite to and shorter than the insulation w, the whole contactor assuming the form of a cylindrical drum.

In the normal position, as shown in .Fig. 3a, contacts 14 and 15 are bridged by strip contact u, thus maintaining the circuit at this point for the vent valve. In the operated position, as shown in Fig. 3?), contacts 14 and 15 rest on the insulated portion to, thus breaking the circuit of the vent valve. However, in this operated position contacts 12 and 13 are bridged by the short strip contact uZ. It can be seen, that the relative position of contacts a and id is such that they cannot bridge their respective contacts 14-15 and 12-13 simultaneously, no matter what the position of the acknowledging device.

The sylphon-operated contactor B comprises a housing 84 in which is mounted a sylphon 83 normally under equal air pressures inside and out. The sylphon carries a cap 82 to which is attached a stem 81 which slidably extends through the housing (by means of a substantially air-tight bushing 85) and supports an insulated disc contact 3. The stem 81 is surrounded by an adjustable coil spring 80 which abuts against the bushing and the cap and normally holds the disc contact 3 in its lowermost position. Pneumatic connection is made with the'sylphon-opera-ted contactor by means of pipe 0 which communicates with the chamber 04 inside the sylphon, and pipe 51 which communicates with the chamber 54 outside the sylphon. The operation ofthe sylphon-op erated contactor depends upon a difierential of pressure in the chambers c4 and b4.

The differential of pressure in the chambers 0-4 and b--4 is obtained when an automatic brake application takes place. To achieve this various apparatus can be used as, for instance, described in my co-pending application S-er. No. 183,193 of April 12, 1927, and, as governing pressure, for instance equalizing reservoir or brake pipe pressure may be used, although as described in my previously referred to application other governing pressures may be employed.

Normally both chambers are maintained at equal pressure, but in case an automatic brake application takes place a pressure diiference between chambers c'4 and b-4 is established with the consequent upward motion of contact 3.

Two lower contacts 10 and 11 are normally connected with each other by the disc contact 3 which connection, however, is broken when in case of an automatic brake application contact 3, due to the differential of pressure in chambers b4 and 0-4, is moved upwardly. When this pressure difference has reached a certain value, depending upon the adjustment of the spring 80 the contact 3 bridges a pair of upper contacts 8 and 9.

The speed governor M is driven in any well known manner, and is provided with a fixed contact 111 and a speed contact 110. Below a predetermined low speed, which usually would be between 10 and 20 M. P. H., depending upon the requirement, the contact 110 is held by a spring against its co-operating contact 111. Above this predetermined speed this contact is open.

A warning device which may be audible, visible, or both, and which is represented in the drawing by the audible signal K, is provided. When the relay R is de-energized and drops its armature 1, the circuit of signal K is closed as follows:

From plus battery, through signal K, con tact 5 and armature 1 back to negative battery.

A time delay is preferably provided between the de-energization of the 'vent valve and the automatic application of the brakes. This time delay may be varied from the fraction of a second to several seconds, depending on the requirements. There are many known ways to provide such a time delay, as, for instance, by the means described in my above referred to application Ser. No. 183,193 of April 12, 1927.

The re-energizing circuits of the relay R, of which there are three, all of which go through the normally open contacts 12 and 13 of the acknowledging device F, will now be discussed.

The first of these circuits is the forestalling circuit, which goes from the plus side of battery H through contacts 13 and 12- bridged by contact strip a in the operative position of the acknowledging deviceto contact 11, disc contact 3 and contact 10 of the sylphon-operated contactor, through relay R back to the negative side of the battery. As appears from the foregoing, this circuit will re-energize the relay R upon manual operation of the acknowledging device, provided contacts 10 and 11 are bridged by disc contact 3, which in turn means tiat forestalling can only take place as long as the air pressures in chambers 04 and 64 are equalized, thus before an automatic brake application has started.

The second re-energizing circuit of the relay R is the resetting circuit which is identical with the forestalling circuit except that it includes the normally open contacts 8 and 9 of the sylphon-operated contactor instead of its normally closed contacts 10 and 11.

The resetting circuit is completed when besides the acknowledging device being placed in its operative position the contacts 8 and 9 are bridged by the disc contact 3. This means that the pressure difference between chambers c4 and 54 has reached a certain value determined by the adjustment of spring 80 or, in other words, that a predetermined amount of brake application has taken place. The third resetting circuit is in multiple with the contacts of the sylphon-operated contactor and goes through the low speed contacts 110 and 111. This circuit is closed when the acknowledging device is placed in operative position, provided the speed. of the train is below its low speed limit.

Under normal conditions the stick relay is energized and its armatures 1 and 2 are attracted; the acknowledging device F being in its normal position, contacts 14 and 15 are bridged by strip contact a and the circuit of the vent valve coil 20 is closed.

Upon passage over an active track element, contactor a is attracted as previously described, breaking the stick circuit of relay E. This in turn deenergizes the vent valve V and simultaneously energizes the audible signal K giving warning to the engineer of the danger conditions ahead and that an automatic brake application will be effected unless forestalling action is taken by him.

Assume now that the engineer is not prepared to heed such warning or is incapacitated to do so; an automatic brake application will then occur.

However, if the egineer is alert and wishes to take advantage of the forestalling privilege, upon receipt of the warning given by the audible signal K, he will move the acknowledging device F into the operative position and immediately afterward will release it. This intermittently breaks the contacts 1 l15 and bridges contacts 12 13 of the acknowledging device. The bridging of the latter contacts will re-energize the relay R providing that disc contact 8 has remained in its normal position, and bridges contacts 10 and 11, which is the case if the acknowledging device has been operated before an automatic brake application has been started. Release of the acknowledging device bridges contacts 14 and 15 and armature 1 being again in its attracted position the vent valve is i e-energized.

If on the other hand the engineer fails to forestall an automatic brake application, he may re-energize relay R through the reset circuit by operating the acknowledging device after a sufficient amount of braking has taken place to move disc contact 3 into a contacting position with contacts 8 and 9.

As described herebefore and illustrated in Fig. 1 the low speed contact by-passes both pairs of contacts of the sylphon-operated contactor. Operation of the acknowledging device thus re-energizes relay R irrespective of whether a brake application has started or not and irrespective of the amount of braking, provided the train is proceeding at below the low speed limit; it should be understood, however, that such speed operated contactor is an optional feature which may be omitted if so desired.

As previously stated, contact 3 of the sylphon-operated contactor is moved upon a differential of pressure in chambers 04 and 64. Such difference in pressure will always exist in the case of automatic brake application but, if so desired, arrangement can be made that it also take place in case of a manual brake application, in which case the resetting will depend on the sum of the automatic and manual brake applications.

Various modifications both in regard to the circuits as well as the physical embodiment of the devices may be employed without deviating from the spirit of my invention, and no undue limitation should therefore be deduced from the specific illustration given but the appended claims should be construed as broadly as possible in view of the prior art.

What I claim as new and desire to secure by Letters Patent is 1. In an automatic train control system comprising a normally active relay de-energized when a receiver on the locomotive registers inductively to form a magnetic couple with a traffic controlled element, a brake initiating circuit controlled thereby, and a restoring circuit for said relay including manually operated normally open contacts in series with normally closed pneumatically operated contacts the latter being paralleled by speed controlled contacts.

2. In an automatic train control system comprising a normally active relay de-energized when a receiver on the locomotive registers inductively to form a magnetic couple with a traffic controlled element, a brake initiating circuit controlled thereby, a restoring circuit for said relay including manually operated normally open contacts in series with normally closed pneumatically operated contacts the latter being paralleled by speed controlled contacts, and means for opening the brake initiating circuit when the restoring circuit is closed.

8. In an automatic train control system comprising a normally active relay de-energized When a receiver on the locomotive registers inductively to form a magnetic couple with a trafiic controlled element, a brake initiating circuit controlled thereby, and a restoring circuit for said relay including manually operated normally open contacts in series with normally closed pneumatically operated contacts the latter being paralleled by speed controlled contacts, and by other normally open pneumatically operated contacts.

4:. In an automatic train control system comprising a normally active relay de-energized when a receiver on the locomotive registers inductively to form a magnetic couple with a traflic controlled element, a brake initiating circuit controlled thereby, a restoring circuit for said relay including manually operated normally open contacts in series with normally closed pneumatically operated contacts the latterbeing paralleled by speed controlled contacts, and by other normally open pneumatically controlled contacts, and means for opening the circuit of the brake initiating circuit when the restoring circuit is closed.

5. In an automatic train control system a normally energized electro-responsive device and a restoring circuit for said device including manually operated normally open contacts, in series with normally closed pneumatically operated contacts, the latter contacts being paralleled by speed-controlled contacts, the manually operated contacts being also in series with other normally open, pneumatically operated contacts.

6. In a train control system a normally energized electro-responsive device having three restoring circuits, one comprising a normally closed air-operated contact, the second comprising a normally open air-operated contact, and the third comprising a speed-controlled contact, each restoring circuit also comprising in common a normally open manually operated contact, re-energization of the electro-responsive device, after its d-e-energization, being only possible if the manually operated contact is simultaneously closed with one of the pressure-operated contacts or the speed-operated contact.

New York, N. Y., July 3d, 1929.

FRANK J. SPRAGUE. 

